Effect of blindfolding on centre of pressure variables in healthy horses during quiet standing.

This research investigates the role of vision in maintaining the balance of horses by examining changes in the center of pressure (COP), concurrently the vertical ground reaction force (GRF), of a standing horse when it is blindfolded. The researchers hypothesize an increase in the magnitude and variability of postural sway variables once visual input is removed.

Understanding the Centre of Pressure (COP) and Ground Reaction Force (GRF)

• The center of pressure (COP) is the point where the resultant of all supporting limbs’ vertical force vectors meet. This point continuously shifts based on a horse’s balance and posture.
• The ground reaction force (GRF) is the force exerted by the ground on a body in contact with it. In this paper, it refers to how the horse’s feet interact with the ground while it tries to maintain its balance.

Stabilographic Analysis

• Stabilographic analysis is a method of assessing balance by tracking the movement of the COP in a horizontal plane. In this study, the researchers used this technique to quantify the changes in a horse’s balance with and without visual input.

Experimental Trials

• The researchers conducted three trials lasting 60 seconds each, under sighted and blindfolded conditions, with COP measurements tracked while the horses were stationary. They then examined variables like the amplitudes and velocities of COP movement in different directions (craniocaudal and mediolateral), mean power frequencies, and the variabilities of these factors.

Findings of the Research

• The removal of visual input increased the magnitude and variability of both the craniocaudal and mediolateral COP amplitudes and the mediolateral COP velocity. This indicates that vision plays a significant role in maintaining a horse’s stability when standing.
• Interestingly, the loss of visual input had a greater effect on time-domain COP variables (amplitudes, velocities) than frequency-domain variables (mean power frequency).

Implications and Recommendations

• The findings of this research suggest that vision plays a crucial role in maintaining a horse’s balance. Any impairment or loss of visual input could significantly impact a horse’s stability.
• Thus, the impact of blindfolding or loss of visual input on a horse’s postural stability should be investigated further, especially when examining horses with neurological impairments that could affect their sense of balance.